sulfatase contributes to systemic activation in pre-pubertal boys

– lessons from deficiency Jan Idkowiak1, Angela Taylor1, Donna M. O'Neil1, Sandra Subtil1, Raymon Vijzelaar2, Renuka P Dias3, Rakesh Amin4, 1,3,6 5 1 6 1 Timothy G Barrett , Jeremy Kirk , Cedric H Shackleton , Celia Moss and Wiebke Arlt (1) CEDAM, Centre for Endocrinology, Diabetes and Metabolism, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, United Kingdom; (2) MRC-Holland bv, 1057-DN Amsterdam, The Netherlands; (3) Centre for Rare Diseases and Personalized Medicine, School of Clinical and Experimental Medicine, University of Birmingham, Birmingham B15 2TT, United Kingdom (4) Department of Paediatric Endocrinology, Great Ormond Street Hospital for Children, London WC1N 3JH (5) Department of Paediatric Endocrinology and (6) Department of Paediatric Dermatology, Birmingham Children’s Hospital NHS Foundation Trust, Steelhouse Lane, Birmingham B4 6NH, United Kingdom Introduction Summary and conclusions

The enzyme Steroid Sulfatase (STS) cleaves groups from esters, including the adrenal androgen metabolite DHEAS, thereby making DHEA available for downstream • We have investigated androgen metabolism in a large cohort of patients with STSD; the cohort is activation towards sex . STS deficiency (STSD) due to inactivating deletions or mutations in genetically characterised and covers two key developmental periods, adrenarche and puberty. the STS gene causes X-linked ichthyosis (OMIM 308100), a skin condition characterized by dry • There are no physical abnormalities in our STSD cohort, including no pubertal delay or clinical signs scales thought to be due to the epidermal accumulation of sulfate. A defect in PAPSS of hypogonadism crucially supporting DHEA sulfation by SULT2A1 - the opposite enzymatic reaction of STS - results in androgen excess due to increased conversion of DHEA to active (Noordam et al., • Sulfated steroids/ androgen precursors are elevated, reflecting the incapacity of de-sulfation in STSD NEJM 2009). • Reduced DHEA (and ) levels indicate biochemical evidence of decreased androgen STS activation by STS

Active Sex • 5α-reductase activity is increased in STSD, suggesting increased androgen activation as a Steroids compensatory mechanism for the decreased availability of precursor steroids for downstream DHEA SULT2A1 DHEAS conversion towards active androgens PAPSS2 • An increased DHEA/DHEAS ratio during adrenarche suggests a distinct role for STS in androgen metabolism before puberty

What is the impact of STS on androgen metabolism during childhood?

Results

Patients characteristics and genetic analysis

• 30 STSD patients (age range: 6-27 yrs) and 38 male, age- and BMI-matched healthy controls. Pre-/peri-pubertal (n=18) Post-pubertal (n=12)

Tvol < 15ml Tvol > 15 ml Tanner PH, G: 1-3 Tanner PH, G: 4-6 Multiplex-ligand-dependent probe amplification (MLPA): • 27 STSD had a complete deletion of the STS gene and the neighbouring HDHD1 gene (90%) • One patient had a partial deletion of exon 7 only • No pubertal delay at present/past medical history Saenger sequencing: • One STSD patient (6.7 yrs) had an undescended left testicle • Two brothers were found to harbour a previously • All patients had an established diagnosis of STSD/XLI based on described missense mutation (p.R454C). typical clinical (n=23) or biochemical findings (n=7). STSD controls

No deletions of further neighbouring gene loci were identified.

Urinary steroid profiling (GC/MS) Serum steroid analysis (LC/MSMS)

Urinary androgen metabolite secretion (µg/24h) DHEAS DHEA * * ** Metabolite Subgroup STSD controls p-value All All all 409 (155, 2192) 403 (117, 2301) 0.82 ***

pre-/peri-pubertal 143 (60, 309) 124 (56, 206) 0.47 post-pubertal 2440 (1521, 3670) 2468 (2035, 3365) 0.87 all 231 (96, 1018) 329 (98, 1569) 0.31

metabolites pre-/peri-pubertal 109 (70, 130) 110 (40, 229) 0.76 Active androgen Active androgen post-pubertal 1021 (917, 1332) 1663 (1045, 2048) 0.16 pre-/peri-pubertal post-pubertal pre-/peri-pubertal post-pubertal DHEA all 207 (117, 716) 43 (10, 165) < 0.001 ** *** *** pre-/peri-pubertal 105 (52, 236) 11 (3, 34) < 0.001 post-pubertal 626 (291, 1905) 165 (62, 784) 0.04 16-OH DHEA all 520 (211, 767) 115 (39, 366) < 0.001 pre-/peri-pubertal 217 (137, 535) 39 (13, 76) < 0.001 post-pubertal 744 (656, 985) 398 (170, 580) < 0.001 5-PT all 160 (83, 318) 51 (13, 163) 0.005 DHEA/DHEAS pre-/peri-pubertal 77 (53, 69) 14 (4, 62) < 0.001 metabolites pre-/peri-pubertal All post-pubertal 338 (189, 792) 234 (78, 366) 0.07 ***

Androgen precursor *** 5-PD all 401 (295, 657) 143 (92, 317) < 0.001 pre-/peri-pubertal 289 (180, 380) 79 (54, 131) < 0.001 post-pubertal 687 (529, 1062) 317 (215, 364) 0.001

*: median (25th, 75th centile) **: Mann-Whitney non-parametric test post-pubertal *

5α-reductase activity (urinary 5α- over 5β-reduced (F) and (B) metabolites)

5αTHF/THF 5αTHB/THB *** *** *** ** ns *

A398 Testosterone Cholesterol-sulfate

All All ***

STSD controls STSD controls STSD controls STSD controls STSD controls STSD controls Q57 All pre-/peri- post- All pre-/peri- post- pubertal pubertal pubertal pubertal E398 pre-/peri-pubertal post-pubertal *

Acknowledgements: